% , True, False , EndOfFile , Infinity , Pi , Undefined .

# Constants

% | Previous result
True, False | Boolean constants
EndOfFile | End-of-file marker
Infinity | Constant representing mathematical infinity
Pi | Mathematical constant, pi
Undefined | Constant signifying an undefined result

###

% -- Previous result

Internal function

##### Calling format:

    %

##### Description:

`%` evaluates to the previous result on the command line. `%` is a global variable that is bound to the previous result from the command line. Using `%` will evaluate the previous result. (This uses the functionality offered by the `LazyGlobal` command).

Typical examples are `Simplify(%)` and `PrettyForm(%)` to simplify and show the result in a nice form respectively.

##### Examples:

    In> Taylor(x,0,5)Sin(x)
    Out> x-x^3/6+x^5/120;
    In> PrettyForm(%)

         3    5
        x    x
    x - -- + ---
        6    120

##### See also:

LazyGlobal .

###

True, False -- Boolean constants

Internal function

##### Calling format:

    True
    False

##### Description:

`True` and `False` are typically a result of boolean expressions like `2 < 3` and `True And False`.

##### See also:

And , Or , Not .

###

EndOfFile -- End-of-file marker

Internal function

##### Calling format:

EndOfFile

##### Description:

End of file marker when reading from file. If a file contains the expression `EndOfFile;` the operation will stop reading the file at that point.

###

Infinity -- Constant representing mathematical infinity

Standard math library

##### Calling format:

    Infinity

##### Description:

Infinity represents infinitely large values. It can be the result of certain calculations.

Note that for most analytic functions Yacas understands `Infinity` as a positive number. Thus `Infinity*2` will return `Infinity`, and `a < Infinity` will evaluate to `True`.

##### Examples:

    In> 2*Infinity
    Out> Infinity;
    In> 2 True;

###

Pi -- Mathematical constant, pi

Standard math library

##### Calling format:

    Pi

##### Description:

Pi symbolically represents the exact value of pi. When the `N()` function is used, `Pi` evaluates to a numerical value according to the current precision. This is performed by the function `Pi()` which always returns the numerical value. It is probably better to use `Pi` than `Pi()`, because exact simplification will be possible.

##### Examples:

    In> Sin(3*Pi/2)
    Out> -1;
    In> Sin(3*Pi()/2)
    Out> Sin(4.7123889804);
    In> Pi+1
    Out> Pi+1;
    In> N(Pi)
    Out> 3.14159265358979323846;

##### See also:

Sin , Cos , Precision , N , Pi() .

###

Undefined -- Constant signifying an undefined result

Standard math library

##### Calling format:

    Undefined

##### Description:

`Undefined` is a token that can be returned by a function when it considers its input to be invalid. The resulting output is then "undefined".

##### Examples:

    In> 2*Infinity
    Out> Infinity;
    In> 0*Infinity
    Out> Undefined;

##### See also:

Infinity .